The long-range goal of this project is to provide an understanding of the microcirculatory effects of the anesthetics and the mechanisms responsible for their action, in both the normal and the hypovolemic state. The project is designed to provide direct quantitative microcirculatory data for constant equipotent concentrations of the anesthetic in the normal animal and in the animal subjected to hemorrhagic hypotension. Microvascular data include small vessel diameters, microvascular blood flow, and microvascular oxygen tensions. In addition, survival rates following a standard hemorrhage protocol will be determined in primates and rats exposed to one of several anesthetic agents. Important aspects of the study include: (1) comparison of equipotent concentrations of anesthetic agents; (2) utilization of both a striated muscle and an intestinal microcirculatory preparation; and (3) quantitative measurement of microvascular parameters. These data will complement macrocirculatory observations obtained during constant equipotent anesthetic depth. In addition, the expected results will form a basis for determining the mechanism by which the anesthetics alter the microcirculatory response to hemorrhage, and thus alter the chances of survival following major hemorrhage.